Wind turbines are used for generating electricity or otherwise providing electrical or mechanical power. Wind turbines rely on winds in order to impart rotation of propellers that are carried by a central rotor shaft. The rotor shaft is then operably coupled to a generator in instances where electricity is being generated or to a mechanical apparatus when conversion of mechanical power is desired.
Wind turbines are desirable because of low maintenance costs and the use of available “free” wind in order to generate clean energy. However, since wind turbines rely on wind to generate energy and because the speed of the wind correlates to the efficiency of the wind turbine, having the wind turbine rotate at an optimal speed is desired. When the wind is blowing at too high of a speed, the electricity generated is at a frequency in excess of what is allowed to be transported to the electrical grid. In order to compensate for excess wind speed, some wind turbines employ a mechanical or electrical brake in order to reduce the rotation speed of the wind turbine. These brakes are generally sufficient for controlling the speed, however, they do not capture the energy that would otherwise be created at high wind speeds and instead convert that energy into waste heat. The lack of sufficient rotational speed control causes the inverter downstream of the wind turbine to shut down, thus causing downtime in which electricity is not being generated.
Accordingly, a need exists for a method or apparatus for effectively monitoring the rotation speed of a wind turbine and capturing energy that would otherwise not be generated by conventional devices.